Should she win, she would be the first woman to serve as president of the United States -- and the first presidential spouse to do so as well. President Bill Clinton served two terms from 1993 to 2001.

On Tuesday, Democrat Sen. Barack Obama announced that he was filing papers to form a presidential exploratory committee, a bid to become the first African-American president. (Full story)

And on Sunday, New Mexico Gov. Bill Richardson, also a Democrat, is expected to announce his bid, one that could make him the first Latino president.

Live 'Web chats' start Monday

Bringing "the right end" to the war in Iraq, reducing the deficit, making the country energy independent and health care affordable were issues Clinton touted in her announcement, speaking on a video posted on her site.

"After six years of George Bush, it is time to renew the promise of America," she said.

"I grew up in a middle-class family in the middle of America, and we believed in that promise," the 59-year-old Chicago native said.

"I still do. I've spent my entire life trying to make good on it, whether it was fighting for women's basic rights or children's basic health care, protecting our social security or protecting our soldiers."

On Sunday she'll appear at the Ryan Chelsea-Clinton Community Health Center to discuss legislation that would expand the State Children's Health Insurance Program. The center bears the names of the two Manhattan neighborhoods it serves -- Chelsea and Clinton -- coincidentally, Chelsea Clinton is the senator's daughter's name.

In the video, she invited Americans to join her in a three-night series of live video Web chats beginning Monday.

"So let's talk. Let's chat, let's start a dialogue about your ideas and mine, because the conversation in Washington has been just a little one-sided lately, don't you think?"

She'll travel next weekend to Iowa and later to New Hampshire, two kickoff states for the Democratic presidential nominating process in 2008, according to her campaign organizers.

When Clinton launched her Senate bid in New York in 1999, she began a "listening tour" around the state to explore views on education, business and health care issues.

Her Republican opponent, Rick Lazio, called her a "carpetbagger" because she had not previously lived in New York. But she beat him, becoming the first sitting first lady to win an elected office, and was re-elected last year with 67 percent of the vote.

A crowded field

Clinton's announcement puts her in a big Democratic crowd of candidates.

In a statement released Saturday, Obama said: "Senator Clinton is a good friend and a colleague whom I greatly respect. I welcome her and all the candidates, not as competitors, but as allies in the work of getting our country back on track."

In addition to Obama and Richardson, the field also includes former Sen. John Edwards of North Carolina, the party's 2004 vice presidential nominee, who declared his candidacy late last year; Rep. Dennis Kucinich of Ohio, a liberal critic of the war in Iraq; and Iowa Gov. Tom Vilsack.

Sens. Joe Biden of Delaware and Chris Dodd of Connecticut have also said they will seek the nomination, and other Democrats mentioned as possible candidates include the party's 2004 presidential candidate, Sen. John Kerry of Massachusetts; retired Army Gen. Wesley Clark, and the Rev. Al Sharpton.

Clinton wants troop cap, is wary of al-Maliki

Clinton, who just returned from a trip to U.S. military facilities in Afghanistan, Iraq and Germany, has urged the Bush administration to return its focus to Afghanistan.

She has proposed a bill to cap troop levels in Iraq and require congressional approval before the president may send more troops.

She has also been highly critical of Iraqi Prime Minister Nuri al-Maliki, saying Washington should cut off financial support to the Iraqi government unless it shows commitment to stemming the sectarian violence there.

"I don't have any faith," she said of al-Maliki, when asked by CNN if she had any faith in him.

In 2002, Clinton was among the majority in Congress who voted in favor of authorizing Bush to attack Iraq if Saddam Hussein refused to give up weapons of mass destruction as required by U.N. resolutions.

In a 2005 letter to constituents posted on her Senate Web site, she said that she took responsibility for her vote, which she said she made "on the basis of the evidence presented by the administration."

In turn, she said, "I, along with a majority of Americans, expect the president and his administration to take responsibility for the false assurances, faulty evidence and mismanagement of the war."